We report a case of cystic renal cell carcinoma (CRCC). In general, computed tomography (CT) and magnetic resonance imaging (MRI) are sufficient for diagnosing renal cell carcinoma (RCC). However, we often have difficulty in diagnosing CRCC based on these modalities alone. In the present case, to assess the contrast-enhancement of the cyst wall and the septum, we evaluated the usefulness of CT arteriography (CTA) by selective injection of contrast material into the renal artery. We believe that CTA could be a valid option for preoperative radiological differentiation of CRCC.